Gradings of non-graded Hamiltonian Lie algebras

A thin Lie algebra is a Lie algebra graded over the positive integers satisfying a certain narrowness condition. We describe several cyclic grading of the modular Hamiltonian Lie algebras H(2\colon\n;\omega_2) (of dimension one less than a power of $p$) from which we construct infinite-dimensional thin Lie algebras. In the process we provide an explicit identification of H(2\colon\n;\omega_2) with a Block algebra. We also compute its second cohomology group and its derivation algebra (in arbitrary prime characteristic).Comment: 36 pages, to be published in J. Austral. Math. Soc. Ser.

A dearth of OH/IR stars in the Small Magellanic Cloud

We present the results of targeted observations and a survey of 1612-, 1665-, and 1667-MHz circumstellar OH maser emission from asymptotic giant branch (AGB) stars and red supergiants (RSGs) in the Small Magellanic Cloud (SMC), using the Parkes and Australia Telescope Compact Array radio telescopes. No clear OH maser emission has been detected in any of our observations targeting luminous, long-period, large-amplitude variable stars, which have been confirmed spectroscopically and photometrically to be mid- to late-M spectral type. These observations have probed 3 - 4 times deeper than any OH maser survey in the SMC. Using a bootstrapping method with LMC and Galactic OH/IR star samples and our SMC observation upper limits, we have calculated the likelihood of not detecting maser emission in any of the two sources considered to be the top maser candidates to be less than 0.05%, assuming a similar pumping mechanism as the LMC and Galactic OH/IR sources. We have performed a population comparison of the Magellanic Clouds and used Spitzer IRAC and MIPS photometry to confirm that we have observed all high luminosity SMC sources that are expected to exhibit maser emission. We suspect that, compared to the OH/IR stars in the Galaxy and LMC, the reduction in metallicity may curtail the dusty wind phase at the end of the evolution of the most massive cool stars. We also suspect that the conditions in the circumstellar envelope change beyond a simple scaling of abundances and wind speed with metallicity

Widespread mitochondrial depletion via mitophagy does not compromise necroptosis

Programmed necrosis (or necroptosis) is a form of cell death triggered by the activation of receptor interacting protein kinase-3 (RIPK3). Several reports have implicated mitochondria and mitochondrial reactive oxygen species (ROS) generation as effectors of RIPK3-dependent cell death. Here, we directly test this idea by employing a method for the specific removal of mitochondria via mitophagy. Mitochondria-deficient cells were resistant to the mitochondrial pathway of apoptosis, but efficiently died via tumor necrosis factor (TNF)-induced, RIPK3-dependent programmed necrosis or as a result of direct oligomerization of RIPK3. Although the ROS scavenger butylated hydroxyanisole (BHA) delayed TNF-induced necroptosis, it had no effect on necroptosis induced by RIPK3 oligomerization. Furthermore, although TNF-induced ROS production was dependent on mitochondria, the inhibition of TNF-induced necroptosis by BHA was observed in mitochondria-depleted cells. Our data indicate that mitochondrial ROS production accompanies, but does not cause, RIPK3-dependent necroptotic cell death

Molecular Aspects and Future Perspectives of Cytokine-Based Anti-cancer Immunotherapy

Cytokine-based immunotherapy is a promising field in the cancer treatment, since cytokines, as proteins of the immune system, are able to modulate the host immune response toward cancer cell, as well as directly induce tumor cell death. Since a low dose monotherapy with some cytokines has no significant therapeutic results and a high dose treatment leads to a number of side effects caused by the pleiotropic effect of cytokines, the problem of understanding the influence of cytokines on the immune cells involved in the pro- and anti-tumor immune response remains a pressing one. Immune system cells carry CD makers on their surface which can be used to identify various populations of cells of the immune system that play different roles in pro- and anti-tumor immune responses. This review discusses the functions and specific CD markers of various immune cell populations which are reported to participate in the regulation of the immune response against the tumor. The results of research studies and clinical trials investigating the effect of cytokine therapy on the regulation of immune cell populations and their surface markers are also discussed. Current trends in the development of cancer immunotherapy, as well as the role of cytokines in combination with other therapeutic agents, are also discussed

Polarization and photometric observations of the gamma-ray blazar PG 1553+113

We present the results of an observational photo-polarimetry campaign of the blazar PG 1553+113 at optical wavelengths. The blazar was recently detected at very high energies (> 100 GeV) by the H.E.S.S and MAGIC gamma-ray Cherenkov telescopes. Our high-temporal resolution data show significant variations in the linear polarization percentage and position angle at inter-night time-scales, while at shorter (intra-night) time-scales both parameters varied less significantly, if at all. Changes in the polarization angle seem to be common in gamma-ray emitting blazars. Simultaneous differential photometry (through the B and R bands) shows no significant variability in the total optical flux. We provide B and R magnitudes, along with a finding chart, for a set of field stars suitable for differential photometry.Comment: 4 pages, 3 figures. To be published by Astronomy and Astrophysic

A multi-wavelength study of the unidentified TeV gamma-ray source HESS J1626-490

HESS J1626-490, so far only detected with the H.E.S.S. array of imaging atmospheric Cherenkov telescopes, could not be unambiguously identified with any source seen at lower energies. Therefore, we analyzed data from an archival XMM-Newton observation, pointed towards HESS J1626-490, to classify detected X-ray point-sources according to their spectral properties and their near-infrared counterparts from the 2MASS catalog. Furthermore, we characterized in detail the diffuse X-ray emission from a region compatible with the extended VHE signal. To characterize the Interstellar Medium surrounding HESS J1626-490 we analyzed $^{12}$CO(J=1-0) molecular line data from the NANTEN Galactic plane survey, HI data from the Southern Galactic Plane Survey and Spitzer data from the GLIMPSE and MIPSGAL surveys. None of the detected X-ray point sources fulfills the energetic requirements to be considered as the synchrotron radiation (SR) counterpart to the VHE source assuming an Inverse Compton (IC) emission scenario. We did not detect any diffuse X-ray excess emission originating from the region around HESS J1626-490 above the Galactic Background and the derived upper limit for the total X-ray flux disfavors a purely leptonic emission scenario for HESS J1626-490. We found a good morphological match between molecular and atomic gas in the -27km/s to -18km/s line-of-sight velocity range and HESS J1626-490. The cloud has a mass of 1.8$times 10^4$M$_{odot}$ and is located at a mean kinematic distance of $d$ = 1.8 kpc. Furthermore, we found a density depression in the HI gas at a similar distance which is spatially consistent with the SNR G335.2+00.1. We discuss various scenarios for the VHE emission, including the CO molecular cloud being a passive target for cosmic ray protons accelerated by the nearby SNR G335.2+00.1.Comment: 9 pages, 10 figures, A&A in press, updated to the final versio

A longer vernal window: The role of winter coldness and snowpack in driving spring thresholds and lags

Climate change is altering the timing and duration of the vernal window, a period that marks the end of winter and the start of the growing season when rapid transitions in ecosystem energy, water, nutrient, and carbon dynamics take place. Research on this period typically captures only a portion of the ecosystem in transition and focuses largely on the dates by which the system wakes up. Previous work has not addressed lags between transitions that represent delays in energy, water, nutrient, and carbon flows. The objectives of this study were to establish the sequence of physical and biogeochemical transitions and lags during the vernal window period and to understand how climate change may alter them. We synthesized observations from a statewide sensor network in New Hampshire, USA, that concurrently monitored climate, snow, soils, and streams over a three-year period and supplemented these observations with climate reanalysis data, snow data assimilation model output, and satellite spectral data. We found that some of the transitions that occurred within the vernal window were sequential, with air temperatures warming prior to snow melt, which preceded forest canopy closure. Other transitions were simultaneous with one another and had zero-length lags, such as snowpack disappearance, rapid soil warming, and peak stream discharge. We modeled lags as a function of both winter coldness and snow depth, both of which are expected to decline with climate change. Warmer winters with less snow resulted in longer lags and a more protracted vernal window. This lengthening of individual lags and of the entire vernal window carries important consequences for the thermodynamics and biogeochemistry of ecosystems, both during the winter-to-spring transition and throughout the rest of the year

Measuring cognitive assessment and intervention burden in patients with acquired brain injured: Development of the "How Much is Too Much" questionnaire

Objective: To design and preliminarily test a questionnaire intended to measure patient treatment burden resulting from participation in cognitive assessments and interventions. Methods: An expert consensus process was used to develop the concept of patient treatment burden and to determine the first set of questionnaire items and administration protocol. The pilot questionnaire was administered to 20 patients with mild to severe acquired brain injuries on completion of a 2-h or longer neuropsychological assessment. Following preliminary testing, the questionnaire was revised and re-evaluated by a second expert panel and content validity was assessed. Results: Burden was defined as psychologically and/or physically aversive symptoms in response to cognitive assessment or intervention. The first questionnaire contained 21 items assigned to 3 categories: physical, cognitive, and emotional. Eightyfive percent of patients endorsed symptom level increases, with "tired/fatigued" the most frequently endorsed item (80% of patients). Instructions and test items were easily understood, and the questionnaire was quick to administer. Content validity ratio (CVR) of the revised questionnaire yielded 23 acceptable items and a subset met the highest CVR threshold (>0.78). Conclusion: This patient-reported outcome will ultimately help patients give voice to aversive experiences, and help clinicians and researchers to monitor and adapt assessments/treatments appropriately. Future steps in development are described

Hypercomplex quantum mechanics

The fundamental axioms of the quantum theory do not explicitly identify the algebraic structure of the linear space for which orthogonal subspaces correspond to the propositions (equivalence classes of physical questions). The projective geometry of the weakly modular orthocomplemented lattice of propositions may be imbedded in a complex Hilbert space; this is the structure which has traditionally been used. This paper reviews some work which has been devoted to generalizing the target space of this imbedding to Hilbert modules of a more general type. In particular, detailed discussion is given of the simplest generalization of the complex Hilbert space, that of the quaternion Hilbert module.Comment: Plain Tex, 11 page